>>Try
>>
>>USE
>>SELECT Table_Name as [Table], Column_Name as [Column],
>>Constraint_Name as [Constraint], Table_Schema as [Schema]
>>FROM INFORMATION_SCHEMA.KEY_COLUMN_USAGE
>>ORDER BY [Table], [Column]
>
>Thanks

Didn't have time to test it thoroughly :( Anyway, it gives all the constrains, so you may just drop them using this query.